The high-speed rail is many years away from any construction in Los Angeles, but part of the project involves early investments in projects that will be used later.

The Commercial Street property is part of a plan to build run-through tracks at Union Station, allowing current trains to stop at the station platforms and continue straight through. The trains currently have to back up out of the station, delaying travel by 15 or 20 minutes.

The project will require the tracks to cross above the 101 Freeway, before connecting with existing tracks and creating a loop around Union Station.

"These improvements will accommodate the LAUS [Los Angeles Union Station] run-through tracks and future high-speed rail operations between LAUS and Anaheim," according to a description by the Public Works Board.

The entire Union Station project is estimated to cost $2.75 billion, according to the Los Angeles County Metropolitan Transportation Authority. That includes not only pass-through tracks for the bullet train, but for local transit and Amtrak, as well as other station and highway improvements, officials said. The state rail authority has long said it would cover a significant part of that cost, though the specific amount is still under negotiation.